tolerance and performance (mode of administration) of cyto-selective difluoroethane-based cryotherapy in the treatment of brown spots

Conditions: Lentigo Solar; Senile Lentigo

Summary: cs5_8 study aim to evaluate the tolerance and to adjust the mode of administration of 2 different conditions of cryotherapy treatments applied on the brown spots of the face with 1 prototype (816-v1). each treatment corresponds to a specific frequency of cryogenic spray application. the study will evaluate the following prototype : • prototypes from (816-v1 301) to (816-v1 355)

rational : solar/senile lentigo is a harmless patch of darkened skin. it results from exposure to ultraviolet (uv) radiation, which causes local proliferation of melanocytes and accumulation of melanin within the skin cells (keratinocytes). solar/senile lentigos or lentigines are very common, especially in people over the age of 40 years. solar/senile lentigines are found as groups of similar lesions on sun-exposed sites, particularly the face or the back of hands. cryotherapy is more and more used to improve skin appearance and currently used to treat lentigo spot. however, the cryogenic gas (conventional cryotherapy - liquid nitrogen) creates a dermabrasion of the skin surface and person receiving this kind of treatment presents an impaired skin during a few days following the treatment as temporary damage of stratum corneum, erythema, scars, burns. following the side effects occurring after conventional cryotherapy application, the sponsor has developed some devices using difluoroethane, manufactured by cryonove pharma, already available on the local and international markets, e.g. cryobeauty mains and cryobeauty corps. to continue it research and development activities, the sponsor selected other sequences of a cryogenic spray (1 prototype of devices for face used according to different frequencies of application, i.e. 2 conditions evaluated) which could be used for lentigo treatment with a same benefit for the consumers without any safety outcomes. design: the study performed is a proof of performance designed to be exploratory, interventional study, monocentric, randomized and double blinded. intervention : 1 prototype of devices are evaluated in 2 different conditions. each treatment corresponds to a specific frequency of cryogenic spray application. a total of 42 brown spots are needed (at least 1 brown spot on the face).the 42 brown spots will be randomized between the 2 conditions and will be attributed to subjects according to the number of spots identified by investigator. prototypes (816-v1 301) to (816-v1 355) will be applied on brown pots located on the face. each spot will be treated six times by a defined prototype (always the same device on the same spot all along the study) according to specific frequencies (every week or every two weeks). prior to any study device application, the dermatologist will assess the adverse events and will decide if the period between two consecutive applications should be extended or not.the dermatologist will verify that the skin has not been treated by cosmetic products (no presence of cream that could interfere with the treatment) and is dry. as the study will use prototypes, before each treatment, the prototype will be administered to any surface (in order to purge eventually the presence of air). an operator previously trained by the dermatologist will apply the study device to the patient's face. subjects will be lying down, and the device will be administered upside down. during applications on the face, subjects will wear diving goggles protecting the eyes from cryogenic gas. the patient follow-up visits are from day 0 to 6 months.

Eligibility criteria:
inclusion criteria: * female or male. * ages 30 to 75. * phototypes i to iv (according with fitzpatrick scale) * featuring brown spots (solar lentigos, senile lentigo) on the face ≥ 3 and ≤ 6 mm in diameter (at least 1 spots per subject) * agreeing not to be exposed to the sun (or artificial uv) during the study. * informed, having undergone a general clinical examination attesting to his/her ability to participate in the study. * having given written consent for their participation in the study. * no suspicion of carcinoma after investigation by a dermatologist. exclusion criteria: * having performed cosmetic treatments (exfoliants, scrubs or self-tanners, facials, uv ...) in the month before the start of the study, at the level of the face. * having applied a depraving product in the month prior to the start of the study, at the level of the face. * having performed cosmetic treatments in a dermatologist (laser, intense pulse light, peeling, creams, cryotherapy ...), at the level of the face in the last 6 months. * with dermatosis, autoimmune disease, systemic, chronic or acute disease, or any other pathology that may interfere with treatment or influence the results of the study (people with diabetes or circulatory problems, allergic to cold, raynaud's syndrome...). * receiving treatment by general or local (dermo corticoids, corticosteroids, diuretics ...) likely to interfere with the evaluation of the parameter studied. * participating in another study or being excluded from a previous study. * unable to follow the requirements of the protocol. * vulnerable: whose ability or freedom to give or refuse consent is limited. * major protected by law (tutorship, curatorship, safeguarding justice...). * people unable to read and write georgian language. * unable to be contacted urgently over the phone. for female subjects: * pregnant woman (or wishing to be pregnant during study) or while breastfeeding. * a woman who does not have a contraceptive method.

Keywords: cryotherapy hyperpigmentation skin diseases